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G. M. HOPKINS.

H v M W W WITNESSES INVENTOR I. @j 19.91am w N. PEYEIIS. Piwkx'Lilhogrzphcr. 91am up UNITED STATES PATENT rerun,

GEORGE M. HOPKINS, OF BROOKLYN, ASSIGNOR TO THE ECONOMIC MOTOR COMPANY, OF NEW YORK, N. Y.

STEAM GENERATOR.

SPECIFICATION forming part of Letters Patent No. 388,873, dated September 4, 1888.

Application filed June 29, 1883. Renewed March I, 1898. Serial No. 266,485. No model.)

To aZZ whom it may concern:

Be it known that 1, GEORGE M. HOPKINS, of Brooklyn, in the county of Kings and State of New York, have invented a new and useful 5 Improvement in Steam-Generators, of which the following is a specification, reference being had to the annexed drawings, forming part thereof, in which Figure 1 is an end elevation, partly in section; and Fig. 2 is a partial plan view.

Similar letters of reference indicate like partsiu the difi'erent figures of the drawings.

The object of myinvention is to provide an inexpensive and efficient steam-generator for :5 use in connection with engines of small and medium power, and which will not be liable to destructive explosion.

My invention consists in a series of horizontal tubes forming the steam-room of the boiler and in drop-tubes projecting therefrom at a greater or less angle to the horizontal and crossing each other over the fire.

Three horizontal tubes, A B B, are con nected together at the top at or near one end by pipe-connections G, from which the engine supplypipe D leads. The tubes A B B are connected atthcir lower surfaces near the opposite end by pipe'connections O, which permit of a free circulation of water from one of the tubes A B B to the others. From the exterior horizontal tubes, B B, project drop tubes E E, which are closed at their lower ends, and which cross each other underneath the central horizontal tube, A, and over the fire space of the boiler, and from the lowcrportion of the central tube,A, project droptubcs F F, which alternate with the drop-tubes E E and project outward underneath the horizontal tubes B B.

The drop-tubes E E F F may form any desired angle with the horizontal; but I have found that an angle of about thirty degrees is most favorable to the circulation of water in the drop-tubes and the escape of steam therefrom; but I do not wish to be understood as confining myself to any particular angle for these tubes.

The normal water-level of the boiler is at about the horizontal semi-diameter of the tubes A B B, and when heat is applied to the drops 0 E E F F steam generated in these tubes rises to the upper inclined surface of the tube and follows along that surface to the larger tubes A. B B and escapes through the water con tained in the said tubes to the steam-room of the 5 boiler, while the water from the larger tubes A B B flows down the lower inclined surface to replace the water converted into steam. This construction permits of generating steam without material variations in the water levcl. It allows of the escape to the engine of steam without priming, and the rapid circulation secured in the drop-tubes insures the automatic cleaning of the tubes.

It is obvious that by employing larger tubes A B B, I may insert a greater number of droptubes, and thereby increase the capacity of the boiler without materially increasing its size.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a steam-generator, the combination of two or more horizontal tubes of large diameter, and series of drop-tubes closed at their lower ends and projecting obliquely from the 7 larger tubes and crossing each other below the larger tubes and over the fire, substantially as herein specified.

2. In a steam-boiler, the combination of the large tubes A B B, connecting-pipes G C, and the oblique droptubcs E E, projecting from the tubes A B B, substantially as specified.

- GEO. M. HOPKINS.

Witnesses:

G. DUVALL, Jr., A. A. HoPKINs. 

